


Belonging

by lawismyname



Category: Shingeki no Kyojin | Attack on Titan
Genre: Alpha Erwin Smith, Alpha/Beta/Omega Dynamics, Beta Mike, Eren is such a bae, Erwin is a pervert when it comes to Eren, Everyone Wants Eren Yeager's Booty, Idk 'coz Eren is kid now because you know Hanji..., M/M, Omega Eren Yeager, Pedophilia?, Polyamory but not really???, it's complicated - Freeform
Language: English
Status: Completed
Published: 2016-10-25
Updated: 2016-10-25
Packaged: 2018-08-24 15:00:35
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,889
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/8376571
Author URL: https://archiveofourown.org/users/lawismyname/pseuds/lawismyname
Summary: Eren's body had changed to a child's due to Hanji's experiment and his worried alpha fetches him and smut ensues!!!





	

**Author's Note:**

> Just a continuation to my other fic, Anything for you.  
> Like I said I love shipping Eren with everyone, and here's another fic with my favorite secret (but not so much) pairing MIKEREN!! XD  
> Please enjoy, and be warned this has pedophilia, I think since Eren became a kid again wat eber..,  
> So be guided accordingly, and no hate comments. Thank you!!!

Erwin stood near the wooden desk and took in the transformed body of Eren Yeager. Though he didn't approve what Hanji had done to the young recruit, he can't say that he wasn't exactly delighted with its results. The lithe and toned body was gone, replaced by supple flesh and baby fat, but despite that he found the plump skin utterly delicious. He had been discreet about his desires and not once had he thought of feasting, even with just his eyes, a young child until the moment Eren came to his life.

It wasn't a big secret, his and Eren's relationship. The corporal, the squad leaders and a few recruits (consisted of Eren's closest friends), knew about them, but no one knew about Mike's participation in their nightly activities.

The beta somehow wanted to keep it a secret, and the reason for that, Mike had not told or hinted. But Erwin didn't force him to, as long as Eren was willing to be his, even if he had to share him with Mike, he's fine with it.

The young brunet sat quietly on a chair, ignoring Hanji's rant as his alpha scrutinized his figure. He likely knew that his alpha was worried of him, and the weight of disappointment clung to his chest. It had been Hanji's fault that Eren got caught in this situation. They were experimenting on some kind of chemical solution, choosing the young recruit as the perfect specimen to test the effects of their concoction.

Yet Eren felt a little responsible. He had been careless enough to drink a tea served by the mad scientist, and it was too late for him to realize that there was an added ingredient when smoke bellowed from his body. Eren had shrunk back to a much younger form, with his memories completely intact (thank goodness, what trouble it would be because children are quite a handful and not to mention a titan shifter at that would make everything hell if he ever transform and have a tantrum) it made things easier to settle out the trouble of explaining the situation he was in.

Erwin had come as soon as he heard word of the little experiment. Eren knew that the alpha was stressed and tired from work, and now, he just added another problem to the commander.

Hanji merely thought it was amazing, their eyes gleaming in wonder as they scribbled their notes with a line of drool trailing down their mouth. Levi had already left their laboratory with a foul mood, grumbling about 'being tired of their shits' and stalked off the room to look for clothes that would fit the young shifter's new body.

Hanji assured them that the change would be only temporary since they used a weak dose for the test, and that Eren would probably transform back to normal after a few days.

Erwin was glad for that at least, and decided to free Eren from any activities that day since it’s likely that he wouldn't be able to train in his state, designating Eren to his care for the time being . It earned them a playful remark from Hanji about 'liking them so young' to which he dutifully ignored.

He moved closer to his omega, hinting the anxiety and fear from his scent. Erwin placed a hand on Eren's head, ruffling the tuft of hair. He crouched down and reassured him that it was fine, and he shouldn't be blamed. Erwin knew Eren had a tendency to blame to himself and Erwin wanted nothing more but to ease his omega's worries.

Levi had returned with some fresh clothes and Erwin bit back an impulsive growl as he caught the look of desire as grey eyes trailed on the flawless patch of skin of Eren's neck. It was fine if it was Mike but with another alpha, his instincts snapped and possessiveness burned to his core as his wolf reacted to the competing alpha. At least with Mike, he could trust him not to mark Eren as mates since they had an agreement but Levi didn't and that made him quite a formidable alpha and it caused Erwin's hackles to rise.

He and Eren decided not to mark each other, not until everything was resolved and humanity has obtained freedom. They had a great responsibility to fulfill and being mated for life would only cause them misery for now. For who knew what could happen with the next expedition. Their lives were barely hanging on a thread, and it was Erwin who does not want Eren to suffer the extreme pain losing a mate if he ever lost his life in the field. He wanted him to have the choice to find himself another lover to replace him, but for now he'll keep his omega and treasure their moments together with the time they have left.

He and Eren then left to his office as soon as he gathered the pile of clothes for his omega altogether with the pants that were now too loose to for his hips. A smirk formed on lips but it was so easily obscured by the calm expression on his features as his eyes glanced towards Eren, hand squeezing the little one that Eren offered as they walked through the corridors.

Opening the door of his office, he invited the omega inside the room. He led him to the bedroom conjoined to his office, setting the clothes to a nearby cabinet and lifted Eren up on his arms, placing him on his lap as he seated at the edge of his bed.

The once snug shirt was too huge for him that it slid to expose a vast amount of skin of Eren's shoulder and chest and Erwin could almost see his brown nub peeking out.

His legs were shorter and thighs more plump, and his cheeks were round with baby fat. Green eyes, much wider than their previous size peered at him curiously and suspiciously as he caressed a rosy cheek with his calloused hand.

He wasn't actually into children but since its Eren, he decided that he didn't mind and might as well as take the opportunity.

Mike would later join them, having to know that he'll likely head to Eren as soon as he would hear the news but for now he'll enjoy his moment alone with his precious omega.

"Umm, Commander Erwin is there something on my face?" The brunet asked, and he shook his head in reply, briefly brushing a thumb over the soft pink lips.

”You look pretty Eren. I didn't know you were so adorably lovely at this age," He spoke and the brunet blushed at his praise, a shy smile on his lips. Erwin brought Eren closer to his chest and nipped the shell of the other's ear.

Eren gasped, his small hands wrung the crisp white shirt and Erwin moved to his lips, tasting his omega's lips with tongue worming into the sweet hot cavern of Eren's mouth.

"Eren, love, would you do something for me?" His words vibrated in between their lips, and Eren nodded, knowing that he couldn't deny his alpha's wishes. He wanted to please his alpha and Erwin took advantage of that, and requested Eren to stand in front of him.

Eren obeyed the older man, and he fidgeted under the scrutinizing gaze of his alpha.

Eren had an idea what Erwin was planning but nevertheless he wasn't against of it. His alpha wanted him and it made him hot and hard just imagining himself with Erwin's strong body overwhelming , ravishing him and Mike would come into the scene, with him still filled with his alpha's cock, seed and knot.

Those thoughts made Eren blush, and Erwin took notice of this.

"Oh? What did you just thought of Eren? Something naughty from the look of you face, isn't it?" He smiled when the brunet replied him with a meek 'yes' and he reached over the exposed shoulder, squeezing it before he slipped his hand to rub the little nub on the omega's chest and received himself a needy whine.

Retracting his hand, he pulled off the shirt of his omega then threw it to the floor. He immediately caught sight of Eren's little cock, already half mast in between his chubby thighs. Eren circled, displaying himself in a languid circle. Erwin licked his lips, his crystal blues eyes clouded with lust, and seemingly pleased as they hungrily took in every inch of the other's body, burning them to memory.

”On the bed now, love. Let me see that lovely hole." Eren nodded, climbing up the bed with his knees and hands on the mattress, wiggling his ass up in the air for his alpha to see.

"Lovely," Erwin breathed. Hands reached the perky globes and he squeezed them, kneading and spreading them apart to see the puckered pink hole that was twitching and already leaking with natural lubricant. Eren's body shape and size may have changed but its omegan physiology was still in function, reacting to his ministrations.

Teeth found purchase on the supple cheeks, leaving prints of teeth and red patches as he sucked the surface. He teased the rim with lingering touches and circles before he dipped a finger inside. His cock twitched at its renewed tightness, and rubbed the tip of his finger on the bundles of nerves.

"Oh? Already wet love? It seems like I can't ignore this. Would you like me to fuck you?" Eren whimpered, rutting his ass back on Erwin's finger as he nodded frantically.

"P-please, alpha. Wreck me, fuck my hole," The omega pleaded, moaning when another finger was inserted.

"Heavens, you smell wonderful. " Erwin sniffed his omega's ass, tongue out to lap that sweet juice. His omega clenched  briefly at the contact. He nudged it into the tight ring, worming it inside and thrusted it in time with his fingers.

Eren pushed his bottom back towards the alpha's mouth, his voice much thinner and higher with the transformation. It would likely hurt this time if Erwin would put his cock in but somehow he didn't care. He wanted Erwin inside, painting his walls with his knot swelling at the brim.

After a fourth, Erwin pulled his fingers out and slipped himself out of the restricting clothes. Eren turned to him, hands already wrapped around the impressive length of his alpha. Sticking his tongue out, he gave the bulbous head a long lick, teasing the slit with his tongue.

Relaxing his jaw, he took in more of Erwin's impressive cock. His little mouth strained from its size. His small hands grabbed what he couldn't swallow and stroked the base, hollowing his cheeks and bobbed his head in time with his movements.

Erwin groaned and watched his omega suck his cock like a child with his favorite candy. His big cock could barely fit inside that pretty mouth. He was about a few inches in, and Eren already looked so full and contented, his mouth creating lewd slurps and squelches as he continued to please him.

"Eren. Fuck, so good. You love sucking alpha's cock do you?"He rasped, and groaned when the tip brushed against the younger's throat.

Grabbing a handful of chocolate hair, he pulled out, his omega whining in disappointment with the loss of his member on his mouth.

The older man bowed down, catching the other's mouth and kissed him hungrily. Eren responded happily, nipping his alpha's lips and tongue mingling with the larger muscle as it fucked his mouth.

"Erwin, please fuck me. I want you inside now. Make me your bitch please." Eren purred against his chin, rubbing scent on him that made the alpha rumble in satisfaction, locking the younger body in a possessive grip.

Positioning Eren with his back flush against his chest, he guided him down on his hard cock, slipping slowly to ease the pain of his penetration and murmuring dirty promises behind Eren's neck to distract him, kissing and grazing his teeth over the sensitive scent gland.

His tongue ran down the curve of his neck, the taste of salt and a unique flavor that was wholly Eren's, bursted in his taste buds. He tasted absolutely delectable with his scent curling into the air, rich and thick with its sweetness.

Lifting Eren by the thighs, he moved in a steady pace, jerking his hips upwards as he slid his omega lower to his lap. Loud moans and pleas escaped Eren's lips, and it encouraged him to increase his pace, shifting his hips slightly in hopes of hitting that sweet spot that would make his omega drown in bliss.

A scream notified him that he had found it, and deliberately he repeated his movements, plunging his throbbing cock deeper inside his beautiful omega. Nails bit the skin of his arms, and Eren threw his head back as he pushed harder, his balls slapping loudly. Arching his neck, the omega caught his lips and initiated a slow kiss with their tongues lapping lavishly against each other.

Sweat coated their flushed skins, and Erwin reveled himself with the lascivious song bursting by each pound and snap of his hips. He could feel the walls flutter around him, signaling Eren's impending climax. With a few more thrust, Eren stilled in his arms, breast out as his back bended to a glorious curve.

The tightness and the wrecked expression on his omega's face brought him closer to his end, and he plunged hard inside the welcoming cavern and spilled his warm cum in thick spurts. He felt Eren convulse against him, moaning with each jerk of his cock.

A creak brought their attention on the bedroom's entrance, finding Mike watching them intently, his own member already bulging against his pants.

 

Words were not needed as Mike proceeded into the room, staring at the omega with a hungry look in his eyes. Eren's scent beckoned him to come closer. Surely one couldn't deny such intoxicating scent overflowing in the air. He had always found Eren's scent exquisite, an addiction to which had led him to be enraptured by the omega.

Mike wanted him, needed him and he was thankful of Erwin allowing him to be with his omega despite their already established relationship. Mike didn't want others finding out about his affections to the omega. It would be hard to understand a beta loving an omega whom already belonged to an alpha. He would likely be thought of as an interference in their relationship. Betas were not compatible with omegas since they lack some specific anatomy that were needed for proper mating and beta-omega relationship doesn't end well if an alpha was to be involved because omegas would likely chose the alpha due to their compatibility. Yet Eren was different, he wasn't like any omega. He still wanted Mike despite his lacking and accepted him wholeheartedly that not a single complaint or comparison was ever heard from his lips.

Mike felt drunk as his nostrils flared to inhale more of that aromatic scent. His member twitched in response to the scene that devoured his sight. Eren's body was of a child, yet those fierce eyes held the familiar emerald gems and its needy look drew him like a moth to a fire.

He knelt in front of the omega, eyes flickering over the red hole full of cock and knot swelling inside. He breathed against the limp organ in between the thighs and without a second to waste he tasted the white fluid staining the pink head. Eren's moan vibrated inside his ears, and it spurred him to swallow the little cock to hear more of Eren's voice.

"Fuck! Mike! I-I ca-aant!" Eren whispered weakly, face twisting in both pleasure and pain. He lapped the rim, tasting Eren's juices and feeling the muscle contract. He alternately sucked Eren's length and fondled the sensitive balls. It took a moment before Erwin's knot deflated and the alpha slipped out with a loud squelch.

Mike stripped off, lifting Eren to his lap. He seized the bruised lips in a heated kiss, tongue dominating that tantalizing mouth and sucked in that rich scent greedily, nuzzling his nose to its source.

Chest to chest, he nudged the tip of his member to the wet hole, waiting for Eren's permission to enter. The omega nodded at him, and he brought Eren down to his hard cock. A pleased grunt vibrated inside his throat, and he grasped the round flesh of Eren's backside and pulled him up and down his cock.

Despite being stretched by Erwin's knot, Eren's hole was still tight as fuck, urging him to completion with every slide. He was moving faster now, mercilessly fucking that sweet spot over and over, wanting Eren to come with his cock.

"Mike! C-cumming!" Was his warning as Eren wetted his stomach, and he drilled his cock repeatedly before crushing the omega in an embrace with a low moan on his throat as he spilled himself inside.

"Beautiful." He heard Erwin whisper and he received a chaste kiss from Eren as Erwin joined them, smoothing his hands over the omega's back.

Erwin and he shared a look, none of hatred nor competition but of understanding. Eren had never belonged to them, rather it was them that belonged to Eren.

 

 

 


End file.
